Multistage rotary pump



Nov. 13', 1951 M. H. BAKER MULTISTAGE ROTARY PUMP 2 SHEETS-SHEET 1 FiledJuly 31, 1948 INVENTOR MILLARD H. BAKER.

,K/dHw Nov. 13, 1951 Filed July 31, 1948 M. H. BAKER r MULTISTAGE ROTARYPUMP 2 SHEETS-SHEET 2 INVENTOR MI LLARD H. BAKER Patented Nov. 13, 1951MULTISTAGE ROTARY PUMP Millard H. Baker, St. Louis, Mo., assignor toFairbanks, Morse & 00., Chicago, 111., a corporation of IllinoisApplication July 31, 1948, Serial No. 41,831

v 1 Claim. (Cl. 10396) dially inwardly of the pumpin channels isminimized.

It is also an object of the invention to provide a pump of multi-stagetype having the suction and discharge ports of the first stage arrangedsubstantially diametrally opposed to the suction and discharge portsrespectively of the second or subsequent stages, so that the impellershaft will not operate under a side loading due to unbalanced forceswhen the pump is operating.

A further object is to be found in the arrangement in a rotary pump, ofimpeller ring members which are formed and constructed to define thefluid pumping channel for the several stages, and which permit theattainment of a minimum axial spacing of the fluid impellers andimpeller shaft bearings so that it becomes unnecessary to incorporatethe usual intermediate shaft bearing and fluid seal means between thepumping stages.

Other objects reside in the form, construction, arrangement and assemblyof the several pump housing parts and impeller ring members which willsatisfy the foregoing and other objects hereof, particular attentionbeing directed to the exemplary embodiment shown in the accompanyingdrawing, wherein:

Fig. 1 is a, longitudinal sectional elevational view of the pumpassembly;

Fig. 2 is a view of the central portion of the pump housing showing itsexterior formation in full line and its interior arrangement of fluidports and passages in broken line;

Fig. 3 is a further View of the center housing with the end portions andthe ring members removed to show additional features thereof;

. Fig. 4 is a sectional elevational view of the center housing as seenalong the line 4-4 in Fig.3; Fig. 5 is a fragmentary sectionaldevelopment of the discharge port zone in the cross-over passage fromone stage to the next, the passage being formed in the central housingand arranged as shown by Figs. 2 and 4 with this view being taken atline 5-5 in Fig. 4; and,

3 Figs. 6, 7 and 8 are enlarged side elevational views respectively ofthe cover end, intermediate and body end impeller ring members, eachmem- 2 her being shown in correlated positions matching with thesectional view of Fig. 4 so that these rings may be assembled with thering of Fig. 8 behind and the ring of Fig. 6 in front of theintermediate ring of Fig. 7.

With reference to Fig. 1, the pump assembly includes a central housingstructure In having a mounting ba'se H and providing opposite flanges I2and I3 at each end of the impeller ring receiving cylindrical bore l4. Abody structure [5 is flange mounted at the housing flange I2 with atransverse wall It recessed into the bore l4 and formed with a centralstufling box IT. The structure [5 also carries an outboard bearing bossl8 axially spaced from the stuffing box II. The cover structure 20 isflange mounted at the housing flange l3 with a transverse Wall 2|recessed into the bore I4 and formed with a central stuffing box 22. Thecover 20 carries an outboard bearing boss 23 axially spaced from thestufling box 22. The body and cover structures close opposite ends ofthe housing bore l4 to provide a chamber I9 therein. I The impellershaft 24 is mounted at one end in a suitable bearing in cover boss 23and extends through the stufling box 22, the central housing H], theopposite stuffing box H, to and through a suitable bearing in the bodyboss I8. The pro- J'ecting end of the shaft 24 carries a suitable driveplate 25 keyed thereto and arranged for connection with a motor (notshown). Shaft 24 carries a pair of axially spaced fluid impellers 26 and21 which are substantially identical in construction and are formed withfluid impelling buckets or vanes 28 at each side and in the peripheralzone thereof. Impeller 26 rotates be tween a pair of impeller rings 30'and SI, and impeller 21 rotates between a pair of impeller rings 3| and32. In the present assembly, ring 3| is common to each impeller and ispositioned between the impellers 26 and 21. The three impeller rings3|], 3| and 32 are axially fixed between the body structure l5 and thecover structure 20.

It will be noted that the impeller rings 30 and 3| form in assembly acomplete fluid channel 33 for the bucket zone of impeller 26. Similarly,rings 31 and 32 form a complete fluid channel 34 for the bucket zone ofthe impeller 21. In each instance, one-half of the fluid channel isformed in one of the impeller rings, it being noted that theintermediate ring 3| is made axially wider than the body and cover rings32 and 3!] respectively since it provides one-half of each of the fluidchannels. In Figs. 2, 3 and 4, the central housing I0 is 3 shown asbeing formed with a flanged fluid inlet fitting 35 and a similarlyflanged fluid outlet fitting 36 angularly and axially off-set (Figs. 2and 3) relative to the inlet fitting 35. In forming the housing It], theinlet 35 has a divided flow passage defined by the partition 31, andthese branch passages are shown in dotted outline at 38 and 39 in Fig.2. The inlet branches open at the surface of the central housing bore Min ports 4| and 42 (Figs. 2 and 4) and match with suitable ports formedin the impeller rings 30 and 3|, as will later appear. The housing i6 isfurther provided with a spirally directed cross-over passage 43 formedin an enlarged portion 44 thereof. The cross-over passage 43 has asingle inlet port 45 in the surface of the bore M of housing It), andthe discharge from this passage 43 is split or divided (Fig. intobranches 46 and 41; as by the partition 48. These branches open in thesurface of the bore M at ports 56, 5|, respectively. The outlet fitting36 opens in the surface of the bore M at a single port 52.

. Considering Fig. 4, it will be observed that the fluid inlet orprincipal suction port 42 is located diametrally opposite the port 5|,and that the principal discharge port 52 is located diametrally oppositethe port 45 leading to the cross-over passage 43. In the presentembodiment of a twostage pump, the first stage suction port 42 isopposite the second stage suction port 5|, and the first stage dischargeport 45 is opposite the second stage discharge port 52. Comparing Figs.2 and 4, it can be seen that the first stage is provided with branchinlets 4| and 42 and a single discharge 45, and that the second stage isalso provided with branch inlets 50 and 5| and a single outlet 52.

Considering the form and assembly of the impeller rings of Figs. 6 and7, it must be understood that ring 33 of Fig. 6 is normally placed infront of ring 3| of Fig. '7. When so related, the upper surface of ring30, particularly its axial flange 55 abuts the transverse wall 2| of thecover structure 20 (Fig. 1). This flange 55 is notched or cut-away toform an inlet port 56. The port 56 opens to a channel 5! which extendsacross the bottom zone of the ring 30 and proceeds to an inclinedchannel or tunnel zone 58 which passes to the opposite side of the ringand opens into the one-half fluid channel 33 formed by this ring. Thechannel 33 extends about the ring 30 and passes under the inlet channel51 at the tangential zone 59 thereof to open at the outlet port 63. Ring3| of Fig. '7, has an axial flange 6| which abuts the under flangedsurface of ring 30 opposite flange on the latter ring. The peripheralsurface of ring 3| is ported at 62 to open to an inlet tunnel passage 63which is the counter part of inlet channel 51 in ring 30. The tunnelpassage 63 opens into the one-half fluid channel 33. This channel 33 isinclined upwardly from the overlying wall 64 to zone 65 and thereafterproceeds in the plane of the ring 3| to the tangential discharge zone 66and the notched port 61 formed in the ring flange 6|.

It can now be seen that with the ring 30 on top of ring 3| and the tworings placed in the housing ID of Fig. 4, the inlet port 42 willi'e'gisten'with notch 56 of ring 33 and the inlet port 4| (the counterport of port 42 as shown in Fig. 2) will register with the port 62 inring 3|. The fluid flowing into the channel 51 of ring 30 and tunnelpassage 63 of ring 3| (Figs. 1, 6 and 7) will converge at zones 58 and64 respectively to flow into the complete pumping channel 33 at eachside of the first stage impeller 26. The impeller will carry the fluidabout this channel 33 and discharge it at the cooperating tangentialchannels 59 and 66 in rings 30 and 3| respectively for transfer at port45 into the cross-over passage 43 of housing I0. Rings 36 and 3| areeach provided with a locating pin 68 and 69 respectively, which pins fitinto an axially directed groove 16 formed in the bore M of the centralhousing l0 (Fig. 4).

The cooperating relation of rings 3| and 32 will now be described inconnection with Figs. '7 and 8, frequent reference being directed toFigs. 1, 2 and 4 for assistance to a complete understanding thereof. Thefluid discharge from cross-over passage 43 in central housing In isdivided at branch passages 46 and 41 and emerges at ports 50 and 5|respectively. Port 5| is adapted to register with port 12 in theperipheral surface of ring 3| and this port 12 opens to a tunnel passageI3 which is opposite but similar to the first mentioned tunnel passage63. Tunnel passage 13 opens at zone 14 and at the rear side of ring 3|in the one-half fluid channel 34 which is under lying channel 33.Channel 34 is briefly shown at the lower portion of Fig. '7. Thischannel 34 continues around the ring 3| and opens at the tangentialchannel zone 15, this channel zone 15 terminating at the notched port'16. The remaining branch passage 46 and port 50 of the crossoverpassage 43 registers with the notched port I? at the back side of thering 32 in Fig. 8. It will be understood that ring 3| is placed in frontof ring 32 for purposes of this description, and that the locating pin Hfor ring 32 fits into the groove 10 (Fig. 4). The notched port 11 ofring 32 opens to the channel 18, and this channel opens through a shorttunnel zone of angularly or inclined form to the one-half fluid channel34 in the upper face of the ring. Channel 34 is bounded at its peripheryby the flange T9. The inclined tunnel zone before mentioned starts atthe broken line 8|] and opens at 8|, in much the same manner as thatportion 58 of ring 30 is formed. Channel 34 in ring 32 proceeds aboutthe same to a tangential channel portion 82 and a discharge notched port83. The channel portion 82 and port 83 match with the counter parts 15and 16 of ring 3|.

It can now be understood that the fluid passing ports 50 and 5| (Figs. 4and 5) enters rings 32 and 3| respectively at notched port 1! and thetunnel port 12 (Figs. 7 and 8) for converging flow into the matchingfluid channels 34 at each side of the impeller '21. The impeller movesthis fluid toward the tangentially directed and matching channels 15 and82 for eventual discharge at the matching and notched ports l6 and 83.This discharge occurs as a single stream and enters port 52 (Fig. 4) forflow outwardly of the final discharge fitting 36.

The ring 30 is formed with a land surface 85 which is axially spacedfrom a similar land surface 86 on ring 3|, so that when assembled atopposite sides of the first stage impeller 26' a running fit is providedradially inwardly of the bucket zone 28 of this impeller. In a likemanner, a land surface 87! (Fig. 8) on ring 32 is axially spaced from aland surface 88 (Fig. 1) on the ring 3| opposite surface 33 shown inFig. 7 so that a running fitis provided radially inwardly of the bucketzone 28 of the second stage impellerfl; Each of the impeller rings iscompletely open in wardly of these land surfaces and between the axiallyspaced stuffing boxes 11 and 22. During pump operation, this centralarea inwardly of the impeller ring assembly will become flooded and acertain amount of flow or circulation will occur through this floodedarea from the higher pressure zone at the second stage impeller 21toward the first stage impeller 26 which is at a lower pressure.External leakage is prevented by suitable gaskets at the body and coverflanged joints and by the shaft stuffing boxes. Accordingly, loss ofpumping efficiency is very materially lessened by the presentarrangement, and the usually complicated shaft sealing means todistinguish the several stages of pumping effort has been eliminated.

A pump of the above described character may be susceptible of certainchanges and modifications without departing from the scope of thepresent invention as defined in and by the annexed claim.

I claim:

In a two-stage pump, a housing formed as a single casting and having acylindrical bore open at its ends, a fluid inlet passage having portsopening to said bore, a fluid discharge passage having a port opening tosaid bore in a zone thereof axially offset from the inlet ports andangularly spaced therefrom by approximately a right angle, and atransfer passage having an inlet opening to the bore in a zone thereofdiametrically opposite but axially offset from the zone containing saidport of the discharge passage, said transfer passage further havingoutlets opening to the bore in a zone thereof on the side of the borediametrically opposite the side containing said ports of the inletpassage; removable body and cover members closing the open ends of saidhousing bore, a shaft rotatably supported by said members and extendingaxially through said bore, a pair of bucket impellers fixed on saidshaft in the bore, a center ring member and opposite side ring membersall disposed in said housing bore and retained therein between said bodyand cover members; said center ring member and one side ring memberforming an impeller channel for one of said bucket im- 6 pellers andproviding channel inlet port means in communication with said ports ofthe housing inlet passage, and a channel outlet port in communicationwith said inlet opening of the transfor passage; said center ring memberand the remaining side ring member forming a second impeller channel forthe other bucket impeller and providing inlet port means for the secondchannel, communicating with said outlets of the transfer passage, and anoutlet port for the second channel, communicating with said port of thehousing discharge passage; the first said channel and its impellerproviding the first or low pressure stage of the pump and the saidsecond channel and its impeller providing the second or high pressurestage of the pump; said center and side ring members providing annularlands in a running seal with the impellers radially inwardly of thebuckets thereof, and being open radially inwardly of said annular landsthereof to form a leakage chamber about the shaft in said housing boreand extending axially between said body and cover members, the portionsof said impellers extending in said leakage chamber being provided withopenings transversely therethrough; and said leakage chamber beingflooded during pump operation, with the leakage fluid therein subjectedto the pressure differential obtaining between the high and low pressurestages of the pump, such as to result in fluid circulation in theleakage chamber in the direction of the low pressure stage of the pump.

MILLARD H. BAKER.

REFERENCES CITED The following references are of record in the file ofthis patent:

UNITED STATES PATENTS Number Name Date 1,893,616 Ferguson Jan. 10, 1933'2,006,590 Ferguson July 2, 1935 2,034,549 Abramson Mar. 17, 19362,056,553 Abramson Oct. 6, 1936 2,258,416 Leopold et a1. Oct. 7, 19451

